Characterization of silicon 3D pixel detectors for the ATLAS Forward Physics experiment

The ATLAS Forward Physics (AFP) project aims to measure protons scattered under a small angle from the pp collisions in ATLAS. In order to perform such measurements, a new silicon tracker, together with a time-of-flight detector for pile-up removal, are planned to be installed at ~μ210 m away from the interaction point and at 2-3 mm away from the LHC proton beam. To cope with such configuration and maximize the physics outcome, the tracker has to fulfil three main requirements: endure highly non-uniform radiation doses, due to the very inhomogeneous beam profile, have slim and efficient edges to improve the acceptance of the tracker, and provide good position resolution. Recent laboratory and beam test characterization results of AFP prototypes will be presented. Slim-edged 3D pixel detectors down to 100-200 μm were studied and later non-uniformly irradiated (with a peak fluence of several 10¹⁵ neq/cm²) to determine the fulfilment of the AFP requirements.